For some automotive applications, flow-through filter cartridges have been changed so that inlet fluid now flows through radially positioned, spaced inlet ports in the filter cartridge through the inside surface of an annular filter media and out through a centrally disposed, outlet port. The centrally disposed, outlet port is threaded so that these filter cartridge configurations are in many essential ways similar to standard spin-on filter cartridges.
In most prior art spin-on filter cartridges, fuel, lubricating oil or other liquids to be filtered flow radially disposed, spaced apart ports, through a filter media from the outside and exits the filter cartridge through a central port. Production lines have been operating for many years producing these type of spin-on filters.
In order to reduce the number of ports inside of filter cartridge and to take advantage of coalescing filter media in which flow must be from the inside out, it is necessary to reconfigure filter cartridges. To the extent that existing production facilities can continue to be used with as little disruption as possible, the expense of accommodating the new arrangement in which flow of the fluid to be filtered is reversed should be minimized. One way to minimize expense is to use as many conventional components as possible so as to avoid the delay and expense of redesigning components, retooling production machinery and retraining employees. In reconfiguring filter cartridges, it is also preferable to reduce the number of component parts and reduce line labor required for assembly.